Erosion behaviour of micro and nanostructured Cr₃C₂NiCrBSi coating on IN718 alloy via HVOF processing

Abstract Surface degradation of materials due to solid particles (Erosion) in high-temperature environments is a major contributor to wear in applications such as power plants, petrochemical plants, and aeroplane engines. This degradation can result in decreased efficiency, higher maintenance costs, and potential equipment failure. The erosion rate is influenced by a number of variables, including the characteristics of the target material and particle shape, velocity, and angle of impingement. Surface coating, especially HVOF spraying, improves erosion resistance leading to increase the material durability, reducing wear and extending equipment life. The high-temperature erosion behaviour of microstructured and nanostructured HVOF-sprayed Inconel 718 superalloy materials is investigated in an air jet erosion tester. Following the tests, the eroded samples are examined using scanning electron microscopy (SEM), Energy dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD) to analyze the effects of erosion. The results indicate that uncoated samples experience higher erosion rates at all impact angles compared to both coated samples. Erosion rates for both microstructured and nanostructured coated samples are higher at a 30° impact angle compared to a 90° angle, indicating a ductile behaviour in response to impact. The lower porosity of the nanostructured coating is believed to enhance its ability to protect the substrate from erodent particles. The Cr 3 C 2 NiCrBSi nanostructured coating provides better erosion resistance and effectively protects the surface of the Inconel 718 superalloy.